Phosphorescent materials
Novel organic compounds containing a twisted aryl group are provided. In particular, the compounds provided contain a 2-phenylpyridine ligand having a twisted aryl group on the pyridine portion of the ligand. The compounds may be used in organic light emitting devices, particularly as emitting dopants. Devices comprising the compounds containing twisted aryl may demonstrate improved color, efficiency, stability and manufacturing. Additionally, methods are provided for making homoleptic Ir (III) compounds which may contain a twisted aryl.
1. A compound comprising a ligand L having the structure:
wherein B and C are each independently a 5 or 6-membered carbocyclic or heterocyclic ring;
wherein A-B represents a bonded pair of carbocyclic or heterocyclic rings coordinated to a metal M via a nitrogen atom in ring A and an sp 2 hybridized atom in ring B;
wherein A-C represents a bonded pair of carbocyclic or heterocyclic rings;
wherein R a , R b , and R c may represent mono, di, tri, or tetra substitutions;
wherein R a , R b , and R c are independently selected from the group consisting of hydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, arylkyl, aryl, and heteroaryl;
wherein X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , and X 9 are independently selected from carbon and nitrogen;
wherein R 1 and R 2 are independently selected from the group consisting of hydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, arylkyl, aryl, and heteroaryl; and
wherein at least one of R 1 , R 2 , and the R a substituents adjacent to C is not hydrogen;
wherein the ligand L is coordinated to a metal M having an atomic number greater than 40; and
wherein A is pyridine.
2. The compound of claim 1 , wherein only one of R 1 , R 2 , and the R a substituents is not hydrogen.
3. The compound of claim 1 , wherein only one of R 1 , R 2 , and the R a substituents is alkyl.
4. The compound of claim 1 , wherein only one of R 1 , R 2 , and the R a substituents is ethyl.
5. The compound of claim 1 , wherein only one of R 1 , R 2 , and the R a substituents is methyl.
6. The compound of claim 1 , wherein the compound has the structure:
wherein m is the oxidation state of the metal M;
wherein n is at least 1;
wherein L′ is a monoanionic bidentate ligand.
7. The compound of claim 6 , wherein the metal M is Ir.
8. The compound of claim 6 , wherein only one of R 1 , R 2 , and the R a substituents adjacent to C is not hydrogen.
9. The compound of claim 6 , wherein only one of R 1 , R 2 , and the R a substituents adjacent to C is alkyl.
10. The compound of claim 6 , wherein only one of R 1 , R 2 , and the R a substituents adjacent to C is ethyl.
11. The compound of claim 6 , wherein only one of R 1 , R 2 , and the R a substituents adjacent to C is methyl.
12. The compound of claim 6 , wherein the compound is selected from the group consisting of:
wherein R is not hydrogen.
13. The compound of claim 12 , wherein R is an alkyl.
14. The compound of claim 13 , wherein the compound is selected from the group consisting of:
15. The compound of claim 9 , wherein the alkyl is on the pyridine ring.
16. The compound of claim 9 , wherein the alkyl is para to the nitrogen of the pyridine ring.
17. An organic light emitting device, comprising:
an anode:
a cathode; and
an organic layer, disposed between the anode and the cathode, the organic layer further comprising a compound having the formula:
wherein B and C are each independently a 5 or 6-membered carbocyclic or heterocyclic ring;
wherein A-B represents a bonded pair of carbocyclic or heterocyclic rings coordinated to the metal M via a nitrogen atom in ring A and an sp 2 hybridized atom in ring B;
wherein A-C represents a bonded pair of carbocyclic or heterocyclic rings;
wherein R a , R b , and R c may represent mono, di, tri, or tetra substitutions;
wherein R a , R b , and R c are independently selected from the group consisting of hydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, arylkyl, aryl, and heteroaryl;
wherein X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , and X 9 are independently selected from carbon and nitrogen;
wherein R 1 and R 2 are independently selected from the group consisting of hydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, arylkyl, aryl, and heteroaryl; and
wherein at least one of R 1 , R 2 , and the R a substituents adjacent to C is not hydrogen; and
wherein the ligand L is coordinated to a metal having an atomic number greater than 40; and
wherein A is pyridine.
18. A heteroleptic complex having the formula Ir(L A-B ) 2 (L C-D ),
wherein L A-B is
wherein L C-D is selected from the group consisting of
and
wherein R 1 , R 2 , R 3 , R 4 and R 5 are each independently selected from the group consisting of hydrogen and alkyl;
wherein each of R 1 , R 2 , R 3 , R 4 and R 5 may represent mono, di, tri, tetra, or penta substitutions; and
wherein R 1 , R 2 , R 3 , R 4 and R 5 are each independently selected from hydrogen and methyl.
19. The compound of claim 18 , wherein L C-D is selected from the group consisting of:
20. The compound of claim 18 , wherein the compound is: